Laboratory profile after mining dam breach: Brumadinho Health Project results.

Objective: To evaluate changes in selected laboratory tests in the population included in the Brumadinho Health Project, according to the exposure to the dam failure.

Methods: Cross-sectional study carried out on representative sample of residents (≥12 years) in Brumadinho, Minas Gerais, including: 1) non-exposed; 2) directly affected by tailings sludge; 3) residents in mining area. The prevalence of abnormal results of blood count, total, HDL and LDL cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, creatinine, urea, estimate of glomerular filtration rate (eGFR) and high-sensitivity C-reactive protein (hs-CRP) were estimated. The Prevalence Ratios (PR) and 95% Confidence Intervals (95%CI) of having an abnormal laboratory finding were estimated using Generalized Linear Models with Poisson probability distribution. Crude and adjusted models were estimated for age range, gender, diabetes, body mass index, smoking, hypertension.

Results: After adjusting, there was no difference in PR between the three populations for most tests, with the exception of the population residing in an area with mining activity and not directly affected by the mud, with a lower chance of having altered total cholesterol (PR: 0.84; 95%CI 0.74-0.95) and a higher chance of having altered HDL cholesterol (PR: 1.26; 95%CI 1.07-1.50), hs-CRP (PR: 1.19; 95%CI 1.04-1.37), and eGFR <60mL/min/1,73 m2 (PR: 1.51; 95%CI 1.05-2.19).

Conclusion: No significant differences were found in the prevalence of biochemical and hematological alterations between the populations directly exposed and not exposed to tailings. Only the group residing in the mining area had a higher prevalence of alterations related dyslipidemia, renal disease, and inflammation.